Method of transformer construction and device

ABSTRACT

The transformer makes use of a unique cup-shaped fitting which has a central bottom opening defined by a flange made of thinner material so as to grip a primary winding in substantially fluidtight relation so that taunting compound can be effectively introduced into the fitting to complete the transformer.

0 United States Patent 11113,569,885

[72] Inventor Raymond H. Hilgers [56] References Cited mile, UNITEDSTATES PATENTS [211 P 873307 2,914,600 11/1959 Smith et al 336/96X [22]F1Ied Nov. 3, 1969 2,988,715 6/1961 G1zynsk1 et a1 336/96 [45] Patented1971 3 175 176 3/1965 Henschke 336/96X [73] Assignee Precision PaperTube Company Wheeling IL 3,210,701 10/1965 Fastner et a1. 336/96 PrimaryExaminerThomas J. Kozma Attorney--Dawson, Tilton, Fallon and Lungmus [54] METHOD OF TRANSFORMER CONSTRUCTION AND DEVICE 7 Claims, 3 DrawingFigs.

[52] US. Cl 336/96, ABSTRACT: The transformer makes use of a unique cup-29/602, 336/ l 98 shaped fitting which has a central bottom openingdefined by a [51] Int. Cl ..H01f 15/02, flange made of thinner materialso as to grip a primary winding l-IOIf 27/30, l-I0lf 41/00 insubstantially fluidtight relation so that taunting compound [50] Fieldof Search 336/96, can be effectively introduced into the fitting tocomplete the transformer.

BACKGROUND AND SUMMARY OF INVENTION The invention finds particularutility in the manufacture of a high voltage transformer for televisionsets. Such a transformer develops an output of 25,000 volts and it isimportant that such elements be ruggedly constructed. On the other hand,it is equally important from the standpoint of both the manufacturer andthe consumer that these be inexpensively constructed. Through the use ofa unique fitting, both ends are achieved, the thinner deformable flangeportion positionably gripping the primary winding of the transformerwhile sealing against loss of potting compound so that a sturdy, rigidconstruction is achieved.

DETAILED DESCRIPTION The invention is described in conjunction with theaccompanying drawing of an illustrative embodiment, in which:

FIG. 1 is a sectional view of the transformer;

FIG. 2 is an exploded perspective view of the transformer; and

FIG. 3 is an enlarged fragmentary sectional view of the deformableflange of the transformer of FIG. 1.

In the illustration given and with particular reference to FIG. 1, thenumeral designates generally a high voltage transformer which is seen toinclude a generally cup-shaped body 11. In the illustration given, thebody is constructed of flame-retardant polypropylene and has a wallthickness of the order of about 0.050 inch. Excellent results areobtainable with wall thicknesses in the range of 0035-0075 inch. Thefitting 11 includes a general flat bottom wall 12 and a generallycylindrical sidewall 13. As best seen in FIG. 2, the sidewall 13 isinterrupted to provide bulge portion 14 which is advantageouslyemployable as a shield for the extension of the high voltage lead 15. Alow voltage lead 16 is also seen in FIGS. 1 and 2.

In FIG. 1, it will be noted that the opening 17 in the center of thebottom wall 12 has received a primary winding generally designated 18.The primary winding 18 includes as its outer cover a sheet of dielectricpaper as at 19. Also seen in FIG. 1 is a second winding 20 which isgenerally torodial in shape and is disposed annularly relative to theprimary winding 18. In current television parlance, the winding 20 isreferred to as a tertiary winding. A lead or connection 21 interconnectsthe primary with the tertiary winding.

In the process for constructing the transformer 10, the cupshapedfitting 11 is positioned as seen in FIG. 2. Thereafter, the primary I8is introduced into the opening 17 where it is gripped by the angularlyextending flange 22 in substantially liquidtight relation. Thereafter,the tertiary winding 20 is positioned in annular relation about theprimary winding 18 and within the confines of the cup-fitting 11. Itwill be appreciated that in certain instances, the two windings 18 and20 may be previously assembled as a single unit before introduction intothe fitting 11. The windings are electrically interconnected by means ofthe lead 21 which extends through an aperture 23 provided in an off-axisportion of the bottom wall 12. The high voltage lead 15 is positioned soas to lie within the bulge portion 14 and thereafter potting compound inliquid form is introduced through the pipe 24 (see FIG. 2). The pottingcompound flows around the tertiary winding 20 as is seen in FIG. 1 withthe flange 22 serving as a barrier against outflow of the liquidcompound. After the potting compound effectively envelops the windingswithin the fitting 11, the same is subjected to curing as by beingsubjected to oven temperatures of the order of 200 F. for about 15-30minutes. Typical potting compounds are made up of either polyesters orsilicones which are electrically inert.

The liquid potting compound is effectively restrained against outflowfrom the fitting 11 by means of the deformable flange 22. The flange 22,as best seen in FIG. 3 is thinner than the remaining portions of thefitting 11 with which it is integral. Optimum results are obtainablewith thickness of the order of 0015-0030 inch, the flange being moldedintegrally with the remaining portions of the fitting 11 and having aninterior facing surface 25 which is generally parallel with the axis ofthe cup-fitting. This effects a positionable gripping of the winding 18while effecting the above mentioned seal.

It will be noted that the bottom 12 is equipped with a pair of postlikeprojections 26 and 27. The post 26 is notched as at 28 for the receiptof a core piece which extends into the axial center portion of theprimary winding 18 as is designated 29 in FIG. 2. The post 27 serves asa seal for the connector 21 and also is advantageously employable as apositioning means during molding.

lclaim:

1. A method of constructing a high voltage transformer comprisingintroducing a primary winding of generally tubular shape into a plasticcup-shaped fitting having a central bottom opening, said opening beingdefined by a generally circular deformable flange integral with saidfitting whereby said flange deforms to positionally grip said winding insubstantially liquidtight relation, providing a second winding withinsaid cup-shaped fitting concentric to said primary, electricallyinterconnecting said primary and secondary winding, and introducingpotting compound into said fitting.

2. A high voltage transformer device comprising a cupshaped fittinghaving a circular opening in its central bottom, said opening beingdefined by a deformable flange integral with said fitting and extendingangularly relative to said bottom, a generally cylindrical primarywinding mounted in said fitting and projecting on each side of saidbottom while being gripped in substantially liguidtight relation by saidflange, a-

generally torodial tertiary winding mounted in said fitting about saidprimary winding and electrically connected thereto, and plottingcompound filling said fitting about said windings.

3. The device of claim 2 in which said fitting bottom is equipped withan offcenter aperture, an electrical conductor extending through saidaperture connecting said primary and tertiary windings.

4. The device of claim 2 in which said fitting has a generallycylindrical sidewall, said sidewall being interrupted by an integralbulge portion, a'high voltage lead from said tertiary winding extendingout of the bulge portion.

5. The device of claim 2 in which said fitting is equipped with anintegral post portion extending outwardly away from said bottom, saidpost being notched to position a transformer core part.

6. A device for use in a high voltage transformer comprising a unitarycup-shaped fitting constructed of generally resilient thermoplasticmaterial and including abottom integral with a generally cylindricalsidewall, said bottom having a centrally located circular opening withthe opening being defined by a deformable circular flange integral withsaid bottom and extending in angular relation to said bottom, saidflange being thinner than said bottom and sidewall to flexpreferentially into gripping relation with a primary winding positiontherein and prior to potting the same.

7. The device of claim 6 in which the thickness of said bottom andsidewall is of the order of about 0.035 to about 0.075 inch while thatof the flange is of the order of about 0.015 to about 0.030 inch, saidfitting being constructed of polypropylene.

1. A method of constructing a high voltage transformer comprising introducing a primary winding of generally tubular shape into a plastic cup-shaped fitting having a central bottom opening, said opening being defined by a generally circular deformable flange integral with said fitting whereby said flange deforms to positionally grip said winding in substantially liquidtight relation, providing a second winding within said cupshaped fitting concentric to said primary, electrically interconnecting said primary and secondary winding, and introducing potting compound into said fitting.
 2. A high voltage transformer device comprising a cup-shaped fitting having a circular opening in its central bottom, said opening being defined by a deformable flange integral with said fitting and extending angularly relative to said bottom, a generally cylindrical primary winding mounted in said fitting and projecting on each side of said bottom while being gripped in substantially liguidtight relation by said flange, a generally torodial tertiary winding mounted in said fitting about said primary winding and electrically connected thereto, and plotting compound filling said fitting about said windings.
 3. The device of claim 2 in which said fitting bottom is equipped with an offcenter aperture, an electrical conductor extending through said aperture connecting said primary and tertiary windings.
 4. The device of claim 2 in which said fitting has a generally cylindrical sidewall, said sidewall being interrupted by an integral bulge portion, a high voltage lead from said tertiary winding extending out of the bulge portion.
 5. The device of claim 2 in which said fitting is equipped with an integral post portion extending outwardly away from said bottom, said post being notched to position a transformer core part.
 6. A device for use in a high voltage transformer comprising a unitary cup-shaped fitting constructed of generally resilient thermoplastic material and including a bottom integral with a generally cylindrical sidewall, said bottom having a centrally located circular opening with the opening being defined by a deformable circular flange integral with said bottom and extending in angular relation to said bottom, said flange being thinner than said bottom and sidewall to flex prEferentially into gripping relation with a primary winding position therein and prior to potting the same.
 7. The device of claim 6 in which the thickness of said bottom and sidewall is of the order of about 0.035 to about 0.075 inch while that of the flange is of the order of about 0.015 to about 0.030 inch, said fitting being constructed of polypropylene. 